How do I measure the corrosivity of an atmospheric environment?
Assessing the corrosivity of a particular atmosphere is rather simple and two general methods have been developed over the past years. The first method involves the exposure of metallic coupons to the environment to rank the resultant corrosion damage. The second method involves measuring several atmospheric parameters and classifying the atmosphere according to standardized measurements. There have been international standards developed for testing by both methods. One of the coupon based test methods is the CLIMAT test based on the wire on bolt ASTM standard. There is an ISO specification (ISO 9223) for determining a material specific corrosivity of atmospheres based on various atmospheric measurements (relative humidity, sulfur dioxide concentration, and chloride deposition).
